Method of making boilers



1933- G c. WAFTER METHOD OF MAKING BOILERS Filed Sept. 1, 1930 3 Sheets-Sheet l Nov. 7, 1933. 5, WAFTER METHOD OF MAKING BOILERS Filed Sept. 1, 1930 3 Sheets-Sheet 2 14 TTORNE r6 Nov. 7, 1933. G. c. WAFTER 1,934,021

METHOD OF MAKING BOILERS Filed Sept. 1, 1930 5 Sheets-Sheet 3 IN vz/v 70R WIT/V595 Bilge am? Wm W Patented Nov. 7, 1933 UNITED STATES METHOD OF MAKING BOILERS George C. Waiter, Oswego, N. Y., assignor to Pierce, Butler & Pierce Manufacturing Corporation, New York, N. Y., a corporation of York New

Application September 1, 1930. Serial No. 419,125 3 Claims. (Cl. 29-1574) This invention relates to boilers and a method of making the same with particular reference to boilers of the return tube type andthe inner shells or furnaces used therewith.

The principal object of my invention is to provide a boiler and method of making the same which will require a minimum number of operations in the manufacture thereof and which will not require the use of special tools.

This is ofparticular advantage in the case of large boilers although it is also very advantageous in the making of boilers in smaller sizes.

Another object is to provide-a boiler and method of making the same which will permit the use of an auxiliary combustion chamber for the furnace which'is wider than the furnace itself. ,7 This willpermitthe use of wider water legs and more tubes or fines for the heating thereof with a given size of furnace than is pos''- sible with boilers known to the art in which the width of the auxiliary combustion chambers is controlled by the width of the furnace.

H Similarly, if desired, it 'Will be possible to use an auxiliary combustion chamber which is narrower than the furnace.

Another object is to provide a method of making a boiler which will reduce to the minimum the number of separate parts required and the number of joints between the different parts of the apparatus, thereby minimizing the danger of leakage and facilitating the fabrication and assembling of the different partsof the boiler.

Other objects and advantages relate to the size, shape and arrangement of parts and to the operations performed in carrying out my method of manufacturing, all as will more fully appear from the following description taken in connection with the accompanying drawings in Which:

Figure 1 is a vertical section of a return tube boiler taken on the line 1-1 of Figure 2.

Figure 2 is a section one line 22 of Figure 1. a

Figures 3, 4, 5, 5a and 5b are plan views of the blanks used in forming the furnace of the boiler.

Figure 6 is a perspective view of the blank shown in Figure 5 in its'final form.

' Figure 7 is a perspective .view of the blank shown in Figure 4 in its-final form.

Figure 8 is a perspective view of the blank shown in Figure 3 in its final form.

Figure 9 is a perspective view of the completed furnace with the end heads omitted.

Figures 10, 11, 12, 12a and 121) are plan views 7 W of blanks used in making a modified form of furnace. I

Figure 13 is a perspective view of the completed furnace of the modified form with the end heads omitted. Y

Figure 14 is a section on line 14-14 of Figure 13.

For the purpose of explaining my invention, I have here illustrated a return tube boiler, 1

having a wrapper sheet 2 inthe shape of an inverted U.

One endof'the wrapper sheet 2 is closed by the front tube sheet 3 which is secured to the wrapper sheet 2 by welding, riveting or other convenient means. v I

The opposite end of wrapper sheet 2 is closed. by the rear tubesheet 4, also secured to wrapper sheet 2 by welding,rriveting or other means,

The front tube sheet 3 has secured thereto a front smoke box 5 into which the lower tubes 6 lead and from. which the upper tubes 7 lead. The opposite ends of tubes 6 are positioned in the flue sheet of the combustion chamber or furnace hereinafter to be described. 4

To the outer face of rear tube sheet 4 is sethe tubes 7 lead.

The furnaceormain combustion chamber 9 is Y positioned between thezside walls of the wrapper sheet 2 and in spaced relation theretoto form vertically and longitudinally extending water legs 10 and. 11.

The main combustion chamber or furnace 9 comprises acrown sheet 12 and opposed side walls 13 and 14. Adjacent one end of furnace 9 and in communication therewith, is a vertically extending auxiliary combustion chamber, 15 having on one face a flue sheet 16 in which theends of the tubes 6 are secured.

The front ,end of the furnace 9 is provided with a front furnace head 17 having a fire door' opening 18 and a fire door 19.

The rear end of furnace9 is closed by-the rearfurnace head 20. Thefurnace. heads 17 and 20 are secured to the furnace9 as by welding, riveting or other convenient means. i 7

With a fire in the main combustion chamber or furnace 9, the products of combustion will pass from the chamber 9 to the auxiliary combustion chamber 15 thence through tubes 6 to front smoke box 5 from which they will pass through tubes 7 to rearsmoke box 8 and thence to themain flue or chimney,.not shown.

As is well known to the art, the interior of the wrapper sheet 2 is filled with water so that such water may absorb heat units from the furnace 9 and the tubes 6 and "I.

The combustion chamber or furnace 9 and its concomitant auxiliary combustion chamber 15 is made in the following way:-

Referring to Figures 3 to 9'inclusive, I provide a blank 21 rectangular in shape and being provided at one end with a rectangular aperture 22.

The blank 21, originally flat as shown'in Figure 3, is rolled or pressed into the semi-. circular form shown in Figure 3' so that the two longitudinal edges of the blank 21 will form side walls 13 and 14 and the upper portion will serve as the crown sheet,12 the aperture 22 being in the upper side of furnace 9 adjacent crown sheet 12. I

The flue sheet 16 and side walls 23 and 24 of the auxiliary'combustion chamber 15 are formed from a blank 25 shown in Figure 4. The blank 25 has in its lower edge a centrally positioned cut away portion 26 conforming to the curved upper surface of the furnace 9 after the same has been shaped to its final form as shown in Figure 8. 1

To form the side walls 23 and 24, the blank 25'h'as its ends bent on the dotted lines shown in Figure 4 to bring such" side walls 23 and 24 into angular relation with the flue sheet 16, such flue sheet 16 having been provided with apertures 2'7 for theQreception of the ends of tubes 6. v

The top and rear of auxiliary combustion chamber 15 is preferably curved in form and is made from the blank 28 shown in Figure 5.

Blank 28 has a concave cutaway portion 29 conforming in shape to the curvature of the upper surface of furnace 9 when the same isin its final form.

The blank 28 is rolled or otherwise formed into the shape shown in Figure 6, the curvature of its edges 30 and 31 conforming in shape to the curved rear edges of side walls 23 and 24 respectively.-' a

For the purpose of closing the opposite ends of furnace 9, I provide blanks 32 and '33. Blank 32 is provided with a rectangular aperture 34 which functions as the fire door 18 previously described. I i Blank 32' is approximately semi-circular in form with its top edge conforming to the'curvature of theforward end of furnace 9 so that when blank '32 is placed in position against the front end of furnace 9 and welded or otherwise secured in position, it will function as the front head 17 of the furnace 9. I

Blank 33 is also approximately semi-circular in form with its upper edge conforming to the shape of the rear end of furnace 9 so that when it is placed in position against such rear end and welded, bolted or otherwise secured in place, it will function as the rear furnace head 20 of the furnace 9.-

The aperture 22 in the furnace 9 is of such a size and shape that it is contained wholly in the crown sheet 12 of the furnace 9 with its rear edge in spaced relation to the rear end of furnace 9.

The auxiliary combustion chamber 15 may be placed in position on furnace 9] in either of two ways. If desired, a portion of the auxiliary combustion chamber 15 which forms the flue sheet 16 and the sidewalls 23 and 24 may first be placed in position on furnace 9 with the flue sheet 16 facing the front end of furnace 9, and it may then be secured in position by welding or otherwise securing the bottom edges to the registering edges of the aperture 22.

I The rear end of the auxiliary combustion chamber 15 comprising the blank 28 may then be placed in position with its top and side edges in registration with the top edges of the flue sheet 16 and the side walls 23 and 24, and with its bottom edge in registration with the rear edge of aperture 22. It may then be secured in position by welding or other means.

, If desired, :the part formed from blank 28 may first be welded or otherwise secured in position on the part formedQfrom blank 25 which com- ,prises the flue sheet 16 and the side walls 23 and 24, and the" auxiliary combustion chamber 15 so formed may then be placed in position with its bottom edges in registration with the edges of aperture 22 and be welded or otherwise secured in position; r

In Figures 10 to 14 inclusive, I have illustrated a modified form of furnace andauxiliary combustion chamber. Y

In Figure 10, I show a blank 35 having an aperture 36 similar to the aperture 22 in blank 21.' Blank 35 is rectangular in shape but is longer than blank 21 so that there will be the same distancebetweeri the'bottom of the furnace formed from blank-35' and the crown sheet thereof as there is between the bottom of the furnace formed from blank 21 and the crown sheet thereof. This extra length is required because in forming the furnacefrom blank 35 into the shape shown in Figure 13, the crown sheet 37 is concave, curving downwardly into the, main combustion chamber.

The side walls .38 and 39 of the furnace 40 formed from blank 35 extend'vertically in spaced relation and are joined byjthe concave crown sheet 37. 1 v F To form the flue sheet andside walls of the auxiliary combustion chamber 41 carried on furnace 40, I provide a blank 42 which has a downwardly extending approximately semi-circular lip 43 conforming in shape 'to the curvature of the concave crown sheet 37.

The sides 44 and 45 of blank 42 are bent along the dotted lines shown in Figure 11 to a parallel position approximately at right angles to the main'body 46 whichv forms the fiue sheet, apertures 47 being provided in flue sheet 46 for the reception of the ends of tubes 6.

.To form the rear of auxiliary combustion chamber 41, I provide a blank 48 having one end curved in form to correspond with the curvature of the concave crown sheet 37.

Blank 48 is curved, as was blank 28, into a To form a rear closure for the furnace 40, I

provide a blank 51 with its upper edge cutaway to conform to the curvature of the rear end of crown sheet 37.

As in the case of the furnace first described, the aperture 36 is of such a size and shape that it is contained wholly in the crown sheet 37 and is in spaced relation to the rear end of the crown sheet 37.

The furnace 40 may be assembled in the same way as was the furnace 9 by placing the blanks 49 and 51 in position to form the front furnace head and the rear furnace head respectively and then welding or otherwise securing them in position. The flue sheet 46 andthe side portions 44 and 45 may then be placed inrposition with the flue sheet facing the forward end of the furnace 40 and with the lower edges of the flue sheet 46 and the sides 44 and 45 in registration with the forward and side edges of the aperture 36. It may then be welded or otherwise secured in position.

The rear portion of the auxiliary combustion chamber 41 which is formed from the blank 48 may then be placed in position with its upper edge in registration with the upper edge of flue sheet 46, its side edges in registration with the rear edges of side portions 44 and 45 and with its bottom edge in registration with the rear edge of aperture 36. It may then be welded or otherwise secured in position.

If desired, the rear part of auxiliary combustion chamber 41 which is formed from blank 48 may first be secured in position on flue sheet 46 and side portions 44 and 45, and such assembly may then be placed'in position on crown sheet 37 with its bottom edges in-registration with the edges of aperture 36 and welded or otherwise secured'in position.

Although I have not here. illustrated such a modification, it will be obvious from the foregoing description that by modifying the blanks from which the auxiliary combustion chambers 15 and 41 are formed, the resultant auxiliary combustion chamber may be made wider or narrower than the width of the furnace 14 or 40, to permit the use of a greater or lesser number of apertures in the flue sheets without the necessity of varying the width of the main combustion chamber of the furnace. 1

In the finished boiler, the wrapper sheet and the furnace are secured to a base 52.

It will be noted that in the fabrication of my improved boiler there are required only eight major parts; the wrapper sheet 2, the front tube sheet 3, the rear tube sheet 4 and the furnace, comprising the five parts formed from the blanks 21, 25, 28, 32 and 33 or, in the case of the modi-' fication shown, the furnace comprising the five parts formed from the blanks 35, 42, 48, 49 and 51. V

The arrangement of parts here disclosed permits the fabrication and assembling of the boiler with comparatively few machine and manual operations, which tends toward economy and speed in manufacture and, in addition, the number of joints between the different parts going to make up the finished boiler being reduced to a minimum, the danger of leakage in operation is greatly reduced. r

I have here shown a boiler of a particular type and shape, but it will be understood that my invention is adapted to be used with boilers of other types and shapes.

It will also be understood that modifications in the method of making my boiler and the different parts thereof may be made to some extent without departing from the spirit of my invention, for although I have shown and described a'specific structure and form and relation of parts, together with a new and improved method for fabricating and assembling the parts as an exemplification of an embodiment of my invention, I do not desire to restrict myself tothe exact size, shape or arrangement of parts or to the sequence in which the different steps of my method are carried out, as various changes may be made within the scope of the appended claims. l

I claim:

1. The method of manufacturing the furnace' for a boiler which consists in providing a suitable blank, cutting out a section of the middle portion thereof to form an aperture wholly within the borders of the blank and bending the end portions into opposed relation to form side walls, and the middle portion to form a crown sheet, providing a second suitable blank, cutting apertures in the central portion thereof and bending the ends into opposed relation to form the side walls of an auxiliary combustion chamher with the middle portion forming a flue sheet, providing a third suitable blank and bending the same to form the top and rear walls of the auxiliary combustion chamber, and securing the second and third blanks together and to the continuous edge of the first-mentioned blank surrounding said aperture.

2. The method of manufacturing a boiler comprising providing a suitable sheet metal blank, cutting out a section of the blank near one side to form an aperture wholly within the borders of the blank, bending the blank to concavo-con- 120 vex form, and rigidly attaching an auxiliary combustion chamber having flue-receiving openings to the continuous edge ofthe blank surrounding saidaperture.

3. The method of manufacturing aboiler com- 1 5 prising providing a suitable sheet metal blank, cutting out a section of the blank near one side to form an aperture wholly within the borders 'of the blank, bending the blank to concavo 

